Figure 2.

Activation of ICE-like proteases in Jt-Bax cells. (A) Jt-Bax-21 or Jt-H cells were treated with doxycycline or anti-FAS antibody in the presence (solid circle) or absence (open square and diamond) of zVAD-fmk (50 μM, Enzyme Systems Products). ICE and CPP32-like activities were measured using fluorogenic substrates YVAD-AFC and DEVD-AFC, respectively. (B) The cleavage of ICE-like proteases was examined by immunoblot analysis with the antibodies indicated and quantitated by densitometer scanning (Ultroscan XL) using β-actin as a control. Apoptotic degradation of PARP (C) or D4-GDI (D) was analyzed by immunoblot. p85, the apoptotic fragment of PARP; p20, the apoptotic fragment of D4-GDI; Dox, doxycycline; F, anti-FAS antibody.